Corylus plant named ‘Raritan’

ABSTRACT

A new and distinct  Corylus avellana  plant named ‘Raritan’ characterized by a vigorous and upright-spreading growth habit, the production of nuts with round kernels that fall free of the husk at maturity, and a high level of tolerance (quantitative resistance) to eastern filbert blight caused by the fungus  Anisogramma anomala  (Peck) E. Müller.

Latin name: Corylus avellana cultivar.

Variety denomination: ‘Raritan’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Corylusplant, botanically known as Corylus avellana and the designation‘Raritan’, or as ‘Raritan’ Hazelnut (H3FR03P33 Rutgers 1), andhereinafter referred to by the name ‘Raritan’. The new Corylus resultedfrom a controlled cross of the female parent OSU 539.031 (unpatented,unreleased breeding selection) with pollen of OSU 616.018 (unpatented,unreleased breeding selection) made in 2004. Hybrid seeds resulting fromthe cross were harvested in August 2004. They were provided a period ofmoist chilling, subsequently germinated, and the seedlings were grown inthe greenhouse during the summer of 2005. From this cross, a total of 92seedling trees were planted in a research field in East Brunswick, N.J.,in October 2005. ‘Raritan’ was discovered and selected as a single plantwithin that progeny of the stated cross-pollination. It was originallyassigned the designation H3FR03P33, which indicates the field, row, andtree location of the original seedling.

The female parent OSU 539.031 is an unpatented, unreleased seeding. Themale parent OSU 616.018 is also an unpatented, unreleased seedling .Both parents of ‘Raritan’ express a high level of tolerance(quantitative/horizontal resistance) to eastern filbert blight caused bythe fungus Anisogramma anomala (Peck) E. Müller.

The new cultivar was asexually reproduced by rooted suckers and whipgrafting in 2010 through 2015 in East Brunswick and New Brunswick, N.J.The unique features of this new Corylus are stable and reproducedtrue-to-type in successive generations of asexual reproduction.

BRIEF SUMMARY OF THE INVENTION

The following traits have been observed and are determined to be theunique characteristics of ‘Raritan’. These characteristics incombination distinguish ‘Raritan’ as a distinct cultivar:

Vigorous and upright-spreading plant habit.

Yellowish-green to green color of developing and fully expanded leavesduring the spring and summer.

High level of tolerance (quantitative resistance/horizontal resistance)to eastern filbert blight (EFB) caused by the fungus Anisogramma anomala(Peck) E. Müller. The source of this resistance differs from the singledominant allele conferred from ‘Gasaway’ (unpatented, Mehlenbacher etal., 1991), which protects Corylus avellana ‘McDonald’ (U.S. Plant Pat.No. 28,200P3, Mehlenbacher et al., 2016), ‘Wepster’ (U.S. Plant Pat. No.27,141P3, Mehlenbacher et al., 2014), ‘Dorris’ (U.S. Plant Pat. No.25,022P3, Mehlenbacher et al., 2013), ‘Jefferson’ (unpatented,Mehlenbacher et al., 2011a), ‘Yamhill’ (unpatented, Mehlenbacher et al.,2009), and several other Corylus avellana cultivars and pollenizersknown to the Inventors.

Expression of incompatibility alleles S3 and S22 in the styles.

Comparisons in several replicated plantings in East Brunswick, N.J.,show that plants of ‘Raritan’ differed from plants of the Corylusavellana cultivar ‘Barcelona’ (unpatented), ‘Tonda di Giffoni’(unpatented), ‘Yamhill’, ‘Jefferson’, and other cultivars and selectionsof Corylus avellana known to the Inventors, primarily in their responseto eastern filbert blight present in New Jersey, a region where thepathogen is native and highly genetically diverse (Muehlbauer et al.,2019). They also differed in S-alleles, nut size, nut shape, kernelpercentage (ratio of kernel weight to nut weight), frequency of defects(blank nuts, moldy kernels, twin kernels, etc.), time of pollen shed,and length of the husk or involucre.

‘Raritan’ is immediately distinguished from its parents by itsincompatibility allele (S-allele) combinations. ‘Raritan’ expressesS-alleles S3 and S22 in its stigmas whereas OSU 539.031 expresses S2 andS22 and OSU 616.018 expresses S2 and S3. ‘Raritan’ also differs in itsresponse to the disease eastern filbert blight (EFB) caused byAnisogramma anomala. Both OSU 539.031 and OSU 616.018 express a moderatelevel of tolerance to EFB similar to that reported for ‘Sacajawea’ foraverage proportion of diseased wood, which was shown to be 21.0%(calculated by total length of EFB-diseased stems per tree divided bytotal length of shoot growth) (see [0142] Capik, J. M. and T. J. Molnar.2012. Assessment of host (Corylus sp.) resistance to eastern filbertblight in New Jersey. J. Amer. Soc. Hort. Sci. 137:157-172). ‘Raritan’has been shown to be highly tolerant expressing a very low averageproportion of diseased wood of only 0.7%.

For example:

Eastern filbert blight response in New Jersey: In a multi-year trial inEast Brunswick, N.J., the proportion of EFB-diseased wood across thecanopy for ‘Raritan’ was 0.7% compared to 20.4% for ‘Yamhill’, 31.2% for‘Jefferson’, 48.6% for ‘Gasaway’, and 67.0% for ‘Barcelona’.

Pollen shed: ‘Raritan’ typically sheds pollen in East Brunswick, N.J.,2-3 days before ‘Yamhill’ and ‘Santiam’ (unpatented, Mehlenbacher etal., 2007), after ‘Ratoli’ (unpatented, minor cultivar from Tarragona,Spain) and prior to ‘Jefferson’ and ‘Gasaway’. ‘Raritan’ descriptor=5.

Husk Length: ‘Raritan’ is 1.5 times nut length, like ‘Barcelona’, while‘Wepster’ is 2 times nut length.

‘Raritan’ produces kernels that are well-suited for the blanched kernelmarket for use in confections and baked goods. ‘Raritan’ combines veryhigh levels of tolerance to eastern filbert blight (evaluated againstAnisogramma anomala strains present in New Jersey, US) with round nutsand kernels, high kernel percentage, and very good kernel blanching. Thetree is vigorous with an upright branching habit that produces adesirable orchard tree when pruned to a single stem.

Field observations in East Brunswick, N.J., and results fromgreenhouse-based inoculations performed in New Brunswick, N.J., indicatethat ‘Raritan’ expresses a very high level of tolerance to easternfilbert blight (EFB) caused by the fungus Anisogramma anomala. While thecultivar is not immune to EFB, it rarely produces stem cankers and mostthat develop are small in size and lack fully formed reproductivestromata which show limited sporulation, equating to very little to nostem dieback and a greatly reduced canopy inoculum load even wheninfections are present. The high level of tolerance (horizontalresistance) is conferred by both of its unrelated, EFB-tolerant parenttrees, which is unlike the cultivars currently grown in Oregon andWashington protected by the single dominant ‘Gasaway’ resistance allele.EFB is now present throughout the Willamette Valley of Oregon where 99%of the U.S. hazelnut crop is grown and is endemic to the eastern US andsouthern Canada, where it has been historically impossible to growCorylus avellana commercially. ‘Raritan’ was selected in central NewJersey and is adapted to the climate present in this region. Pruning toremove cankers and fungicide applications are currently used to managethe disease in orchards of ‘Barcelona’ and other susceptible cultivarsin the Pacific Northwestern US. ‘Raritan’ is suitable for planting inareas with high EFB disease pressure. It has shown excellent tolerancein the eastern US where the EFB fungus is native and genetically diverse(Muehlbauer et al., 2019).

BRIEF DESCRIPTION OF THE DRAWINGS

The figures include color photographic illustrations that illustrate theoverall appearance of the new cultivar, showing the colors as true as itis reasonably possible to obtain in colored reproductions of this type.Foliage colors in the photographs may differ slightly from the colorvalues cited in the detailed botanical description which accuratelydescribe the colors of the new Corylus.

FIG. 1 is a color photographic illustration of an original unpruned treeof the new cultivar ‘Raritan’ hazelnut in the 15th leaf.

FIG. 2 is a color photographic illustration of nuts, husks, and leavesof the ‘Raritan’ hazelnut.

FIG. 3 is a color photographic illustration of nuts, cracked shells, rawkernels, and blanched kernels of hazelnuts ‘Raritan’.

FIG. 4 is a phenology chart illustration that shows time of femalereceptivity, pollen shed, and vegetative budbreak of ‘Raritan’ and otherhazelnut cultivars.

FIG. 5 is a phenology chart illustration that shows time of femalereceptivity, pollen shed, and vegetative budbreak of ‘Raritan’ and otherhazelnut cultivars.

DETAILED BOTANICAL DESCRIPTION

The cultivar ‘Raritan’ has not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in environment such as temperature and light intensity,without, however, any variance in genotype.

The aforementioned photographs and following observations andmeasurements describe plants grown in East Brunswick, N.J., undercommercial practice outdoors in the field during the spring and summer.Plants used for the photographs and description were the original tree(15 years old) and those propagated by tie-off layerage and growing ontheir own roots (six and seven years old).

Color references herein are made to The Royal Horticultural SocietyColour Chart, 1966 Edition, except where general terms of ordinarydictionary significance are used. International Union for the Protectionof New Varieties of Plants (“UPOV”) descriptors are described in theMar. 28, 1979, UPOV Hazelnut guidelines.

-   Botanical classification: Corylus avellana cultivar. ‘Raritan’.-   Parentage: The female, or seed, parent is Corylus avellana OSU    539.031 (unpatented, unreleased seedling), which resulted from a    cross of OSU 275.031 (unpatented) x ‘Sant Pere’ (unpatented). OSU    275.031 is the result of the cross ‘Montebello’ (unpatented) x OSU    74.037 (unpatented). OSU 74.037 resulted from a cross of OSU 14.084    (unpatented) x OSU 17.068 (unpatented), which are offspring of    ‘Barcelona’ x ‘Daviana’ (unpatented) and ‘Barcelona’ x ‘Tombul    Ghiaghli’ (unpatented), respectively. ‘Sant Pere’ is a minor    cultivar from Tarragona, Spain, known for very early nut maturity    (Tasias-Valls, 1975). ‘Raritan’ is highly tolerant of eastern    filbert blight. OSU 539.031 is reported as similar to ‘Sacajawea’    (as described in Mehlenbacher et al., 2008) and ‘Tonda di Giffoni’    in its response to EFB in Oregon. ‘Raritan’ has shown a much higher    level of tolerance to EFB than both ‘Sacajawea’ and ‘Tonda di    Giffoni’ when grown in New Jersey (Capik and Molnar, 2012). The    male, or pollen, parent is Corylus avellana OSU 616.018 (unpatented,    unreleased seedling), which is the result of a cross of ‘Tonda di    Giffoni’ x ‘Clark’ (unpatented, Mehlenbacher et al., 2001). It was    shown to be tolerant to EFB in Oregon and selected as a    complimentary parent to the unrelated OSU 539.031 to subsequently    enhance quantitative resistance (horizontal resistance) in their    offspring.-   Incompatibility alleles: ‘Raritan’ has incompatibility alleles S3    and S22. Female parent OSU 539.031 has alleles S2 and S22 and male    parent OSU 616.018 has the alleles S2 and S3. ‘Tonda di Giffoni’ has    the alleles 2 and 23, ‘Tonda Pacifica’ (U.S. Plant Pat. No. 22,715,    Mehlenbacher et al., 2011b) and ‘Wepster’ have alleles S1 and S2,    and ‘McDonald’ has alleles S2 and S15.-   Propagation (type rooted suckers):    -   -   Time to initiate roots.—About 30 days at 20° C.        -   Time to produce a rooted young plant.—About six months at            22° C.        -   Root description.—Fine to thick; freely branching; creamy            white in color.-   Propagation (type whip grafting):    -   -   Time to budbreak on the scions.—About 14 days at 25° C.        -   Time to produce a grafted plant.—About six months at 25° C.-   Plant description:    -   -   General appearance.—Natural habit is perennial shrub, but in            commercial orchards, is a single trunk tree; vigorous            upright, spreading plant habit.        -   Growth and branching habit.—Freely branching; about 15            lateral branches develop per plant; pinching, that is,            removal of the terminal apices, enhances branching with            lateral branches potentially forming at every node.        -   Vigor.—Vigorous, upright growth habit.        -   Size.—Plant height is about 6.1 meters; plant diameter or            spread is about 5.5 meters.        -   Trunk at 30 cm above the soil line.—8.6 cm in 2019. Texture            is mostly smooth, glabrous.        -   Trunk color.—197C.-   Lateral branch description:    -   -   Length.—About 40.0 cm; ranges from 30.0 cm to 48.0 cm.        -   Diameter.—About 5.3 mm; ranges from 4.5 mm to 6.5 mm.        -   Internode length (at base).—About 1.0 cm.        -   Internode length (at tip).—About 5.8 cm; ranges from 5.0 cm            to 7.0 cm.        -   Texture.—Smooth, pubescent.        -   Strength.—Strong.        -   Color, immature.—145A.        -   Color, mature.—146C.        -   Color of previous seasons branches.—199D.-   Foliage description:    -   -   Arrangement.—Alternate, simple.        -   Length.—About 14.0 cm; ranges from 12.5 cm to 15.0 cm.        -   Width.—About 12.1 cm; ranges from 11.0 cm to 14.0 cm.        -   Shape.—Oblong to ovate.        -   Apex.—Obtuse to acute.        -   Base.—Cordate.        -   Margin.—Serrate.        -   Texture, upper and lower surfaces.—Slightly pubescent.        -   Venation pattern.—Pinnate.        -   Color, developing foliage.—Upper surface 144C; lower            surfaces, 145B.        -   Color, fully expanded foliage.—Upper surface: spring and            summer, 137B; late summer and fall, 137B.        -   Color, fully expanded foliage, lower surface.—Spring and            summer, 138B; late summer and fall, 138B.        -   Venation, upper surface.—Spring and summer, 145A; late            summer and fall, 145A.        -   Venation, lower surface.—Spring and summer, 145A; late            summer and fall, 145A.-   Leaf bud description:    -   -   Shape.—Globular. Length: average 8.0 mm. Diameter: average            6.0 mm.        -   Time of leaf budbreak.—Medium to late, Descriptor-6.            ‘Raritan’ budbreak is approximately six days before            ‘Jefferson’, about six days after ‘Yamhill’, and two days            later than ‘Santiam’.        -   Color.—145B.-   Petiole description:    -   -   Length.—About 1.6 cm; ranges from 1.0 cm to 2.0 cm.        -   Diameter.—About 2.5 mm; ranges from 2.0 mm to 3.0 mm.        -   Texture, upper and lower surfaces.—Pubescent.        -   Color.—144A.-   Flower description:    -   -   Male inflorescences.—Catkins.        -   Color prior to elongation.—176D.        -   Catkin length.—Average 30.5 mm. Catkin diameter: average 6.5            mm.        -   Female inflorescence style color.—47B. Female inflorescence            length at full maturity: average 7.0 mm.        -   Time of female flowering.—Medium, Descriptor-5.        -   Time of female flowering compared to male            flowering.—Protogyny, Descriptor-1. Time of male flowering:            Early-to-medium, Descriptor-4.        -   Involucre constriction.—Absent.        -   Involucre length.—1.5 times length of nut, Descriptor-7.        -   Size of indentation.—Medium, Descriptor-5.        -   Strength of serration of indentation.—Strong, Descriptor-7.        -   Thickness of callus at base.—Thick, Descriptor-7.        -   Pubescence on husk.—Absent, Descriptor-1.        -   Density of hairiness of involucre.—Weak, Descriptor-3.        -   Jointing of bracts.—On both sides, Descriptor-3.-   Nut description:    -   -   Length.—Average 18.6 mm.        -   Width.—Average 19.1 mm.        -   Depth.—Average 15.9 mm.        -   Nut shape.—Round.        -   Nut shape index.—(Width+Depth)/2*Length=0.94.        -   Nut compression index.—(Width/Depth)=1.21.        -   Nut weight.—Average 2.51 grams.        -   Kernel weight.—Average 1.17 grams.        -   Kernel percentage (kernel weight/nut weight).—Average 46.6%.        -   Number of fruits per cluster.—Two to three.        -   Nutshell coloration.—165B.        -   Number of stripes on shell.—Many, Descriptor-7.        -   Shape of fruit apex.—Flat, Descriptor-1.        -   Prominence of fruit apex.—Slightly prominent, Descriptor-3.        -   Size of fruit pistil scar on shell.—Very small,            Descriptor-3.        -   Hairiness of top of fruit.—Weak, Descriptor-3.        -   Curvature of nut basal scar.—Flat, Descriptor-2.        -   Double kernels.—Absent.        -   Kernel shape.—Globular, Descriptor-2.        -   Shape of kernel in cross-section.—Rectangular, Descriptor-4.        -   Lateral groove in kernel.—Present.        -   Corkiness of pellicle of kernel.—Lightly corky,            Descriptor-3.        -   Disease/pest resistance.—Plants of the new Corylus avellana            exhibit a very high level of tolerance to EFB, referred to            as quantitative resistance or horizontal resistance, caused            by the fungus Anisogramma anomala (Peck) E. Müller. It has            been evaluated against the strains of the fungus present in            New Jersey. A few small cankers may develop under high            disease pressure, but they typically lack stromata equating            to reduce sporulation and subsequent orchard inoculum load.            Plants have not been challenged against all strains of            Anisogramma anomala present in North America and have not            been thoroughly evaluated for their tolerance of bud mites            (Phytoptus avellanae Nal.); no bud mites were observed on            the original tree or its propagules grown in East Brunswick,            N.J. Further, no bacterial blight caused by Xanthomonas            campestris pv. corylina was observed on the cultivar during            the course of evaluations.        -   Temperature tolerance.—‘Raritan’ was selected in East            Brunswick, N.J., and is targeted for production in USDA            Plant Hardiness Zone 6a to 7b. Plants of the new Corylus            avellana have been observed to tolerate temperatures from            −21 to 38° C.

COMPARATIVE DATA

FIG. 4 presents a phenology chart showing time of female receptivity,pollen shed, and vegetative budbreak of ‘Raritan’ and other hazelnutcultivars grown in East Brunswick, N.J. over a time period from Januaryto April of 2018. For each of the different indicated varieties(‘Raritan’, ‘Jefferson’, ‘Yamhill’, ‘Santiam’, ‘Ratoli’ and ‘Gasaway’)upper and lower bar graph pairings are provided in alignment with theirrespective varietal indicators, wherein the upper (top) bar graph ofeach pairing represents pistillate (female) flower development as itprogresses over time through each of four stages represented by thecrosshatchings key at the bottom of the chart; and the lower (bottom)bar graph of each pairing represents staminate (male) flower developmentas it progresses over time through each of three stages represented bydifferent crosshatchings defined by another key at the bottom of thechart. The different respective stages correspond to the stages ofdevelopment as defined and described in “Flowering phenology of easternfilbert blight-resistant accessions in New Jersey,” Capik, J. M. and T.J. Molnar, HortTechnology 24:196-208, 2014 (hereinafter sometimes “Capikand Molnar (2014)”). Stage 1 of vegetative bud development for each ofthe varieties is represented by the solid black rectangles aligned withthe varietal indicators.

FIG. 5 presents a phenology chart showing time of female receptivity,pollen shed, and vegetative budbreak of ‘Raritan’ and other hazelnutcultivars grown in East Brunswick, N.J., from December 2018 to April2019. For each of the different indicated varieties (‘Raritan’,‘Jefferson’, ‘Yamhill’, ‘Santiam’, and ‘Ratoli’) upper and lower bargraph pairings are provided in alignment with their respective varietalindicators, wherein the upper (top) bar graph of each pairing representspistillate (female) flower development as it progresses over timethrough each of the four Capik and Molnar (2014) stages represented bythe crosshatchings key at the bottom of the chart; and the lower(bottom) bar graph of each pairing represents staminate (male) flowerdevelopment as it progresses over time through each of three Capik andMolnar (2014) stages represented by crosshatchings defined by anotherkey at the bottom of the chart. The different respective stagescorrespond to the stages of development described in Capik and Molnar(2014). Stage 1 of vegetative bud development for each of the varietiesis represented by the solid black rectangles aligned with the varietalindicators.

-   -   -   Disease resistance.—‘Raritan’ differs from existing Corylus            avellana cultivars based on its source and type of            resistance to eastern filbert blight (EFB) caused by            Anisogramma anomala. Commercial cultivars previously widely            grown in Oregon including ‘Barcelona’, ‘Ennis’ (unpatented),            ‘Daviana’ (unpatented), ‘Butler’ (unpatented), etc. are            highly susceptible to EFB and cannot be grown in the eastern            US without copious applications of chemical fungicides and            heavy pruning to remove infected stems. Tree death can occur            in the eastern US within 5 years of exposure to the systemic            fungus. The more recently developed cultivars ‘Santiam’,            ‘Yamhill’, ‘Jefferson’, ‘Dorris’, ‘Wepster’, and ‘McDonald’            and their associated pollenizers are protected from EFB by a            single resistance gene conferred from Corylus avellana            ‘Gasaway’. This gene provides a high level of resistance in            Oregon and Washington where the diversity of the fungus is            limited (Muehlbauer et al., 2019), but does not provide a            similar level of protection from disease in the eastern US            where the pathogen is endemic and genetically diverse (Capik            and Molnar, 2012; Muehlbauer et al., 2018). ‘Raritan’            hazelnut is highly tolerant to EFB but does not carry the            single ‘Gasaway’ resistance allele. It was developed by            crossing two unrelated Corylus avellana plants both            exhibiting a high level of tolerance and then selecting            offspring exhibiting enhanced levels of tolerance in the            presence of high disease pressure in East Brunswick, N.J.            While ‘Raritan’ plants are not immune to EFB, they have been            shown to rarely get destructive stem cankers that lead to            stem die-back and subsequent yield decline. In a multi-year            trial in East Brunswick, N.J., completed in winter 2018 and            spanning more than 8 years of exposure to EFB, the average            proportion of diseased wood (total length of EFB-diseased            stems per tree divided by total length of shoot growth) for            ‘Raritan’ was 0.7% compared to 20.4% for ‘Yamhill’            (unpatented, Mehlenbacher et al., 2009), 31.2% for            ‘Jefferson’ (Mehlenbacher et al., 2011a), and 48.6% for            ‘Gasaway’. Previous studies in New Jersey showed the            proportion of diseased wood of ‘Barcelona’ to be 67.0%,            ‘Tonda di Giffoni’ 39%, and ‘Sacajawea’ 21% (Capik and            Molnar, 2012). Differences were also observed in the number            of cankers and average canker length for ‘Raritan’ in            comparison to ‘Yamhill’, ‘Jefferson’, and ‘Gasaway’ in the            study completed in 2018. ‘Raritan’ exhibited an average of            7.0 cankers per tree with an average canker length of            20.3 cm. In contrast, ‘Gasaway’ exhibited an average of 93.0            cankers per tree with an average length of 130.8 cm,            ‘Jefferson’ exhibited an average of 36.9 cankers per tree            with an average length of 72.3 cm, and ‘Yamhill’ exhibited            an average of 40.5 cankers per tree with an average length            of 37.9 cm. As reported in Capik and Molnar (2012), and as a            further point of comparison in regard to EFB response,            ‘Barcelona’ exhibited an average of 20.4 cankers per tree            with an average length of 61.9 cm, ‘Tonda di Giffoni’            exhibited an average of 39.0 cankers per tree with an            average length of 24.5 cm, and ‘Sacajawea’ exhibited an            average of 7.7 cankers per tree with an average length of            21.5 cm (Capik and Molnar, 2012). While ‘Sacajawea’, a            cultivar known to exhibit tolerance to EFB, exhibits similar            canker numbers per tree and canker length to ‘Raritan’, its            proportion of diseased wood is much higher at 21% compared            to 0.7%.        -   Nut and kernel characteristics.—‘Raritan’ hazelnut is            targeted for the blanched kernel market and specifically for            nut production in the eastern United States in USDA Plant            Hardiness Zones 6a to 7b where most existing cultivars of            Corylus avellana cannot be grown due to the impacts of EFB.            The nut shape is round although slightly compressed along            its depth. Kernels are round with a slight point. The            average single nut weight over the past 6 years for            ‘Raritan’ is 2.51 g and average single kernel weight is 1.17            g, with an average kernel to nut ratio of 46.6% (FIG. 3).            ‘Raritan’ nuts and kernels are smaller than those of            ‘Barcelona’, ‘Jefferson’, and ‘Sacajawea’, and also differ            in kernel to nut ratio. For example, ‘Barcelona’ (as            described in Mehlenbacher et al., 2008) had an average            single nut weight of 3.85 grams, average single kernel            weight of 1.66 grams, and an average kernel to nut ratio of            43.1%. ‘Sacajawea’ (as described in Mehlenbacher et            al., 2008) had an average single nut weight of 2.79 grams,            an average single kernel weight of 1.45 grams, and an            average kernel to nut ratio of 52.1%. ‘Jefferson’ (as            described in Mehlenbacher et al., 2011a) had an average            single nut weight of 3.69 grams, an average single kernel            weight of 1.66 grams, and an average kernel to nut ratio of            42.9%. ‘Raritan’ nuts and kernels are relatively similar in            size to ‘Yamhill’, ‘Wepster’, and ‘McDonald’ but differ in            several aspects including ratio of kernel to nut and            pellicle removal after roasting. For example, ‘Yamhill’ (as            described in Mehlenbacher et al., 2009), had an average            single nut weight of 2.34 grams, an average single kernel            weight of 1.13 grams, and an average kernel to nut ratio of            49.3%. ‘Wepster’ (as described in Mehlenbacher et al., 2014)            had an average single nut weight of 2.39 grams, an average            single kernel weight of 1.11 grams, and an average kernel to            nut ratio of 46.6%. ‘McDonald’ (as described in Mehlenbacher            et al., 2016) had an average single nut weight of 2.39            grams, an average single kernel weight of 1.21 grams, with            an average kernel to nut ratio of 50.7%. Raw kernels of            ‘Raritan’ have a light brown pellicle with a moderate amount            of attached fiber (average rating was 2.0 on a scale of 1            [no fiber] to 4 [much fiber] with average based on 6 years            of evaluations). Pellicle removal after roasting at 150° C.            for 15 min and rubbing is rated on a scale of 1 (complete            pellicle removal) to 7 (no pellicle removal). Most of the            pellicle on ‘Raritan’ kernels is removed after roasting with            an average rating of 2.2 (averaged from 6 years of            evaluations). ‘Raritan’ demonstrated better average pellicle            removal than that reported in Oregon for ‘Barcelona’ (4.2            out of 7.0 as described in Mehlenbacher et al., 2008),            ‘Jefferson’ (3.9 out of 7.0 as described in Mehlenbacher et            al., 2011a), ‘Yamhill’ (4.1 out of 7.0 as described in            Mehlenbacher et al., 2011a), and ‘McDonald’ (3.8 out of 7.0            as described in Mehlenbacher et al., 2016). ‘Raritan’ has            similar pellicle removal to ‘Sacajawea’ (2.9 out of 7.0 as            described in Mehlenbacher et al., 2011) and ‘Dorris’ (2.4            out of 7.0 as described in Mehlenbacher et al., 2013),            whereas, ‘Tonda Pacific’ as described in Mehlenbacher et al.            (2011), had superior pellicle removal with a score of 1.5            out of 7.0. The average percentage of good kernels (kernels            free of defects) were calculated for ‘Raritan’ over three            years of evaluation and found to be 88.4%. There was a very            low incidence of moldy kernels (average 0.8%), blank nuts            (0.4%), and shriveled kernels (1.2%). The majority of the            defects were attributed to sucking insect feeding damage,            primarily Brown Marmorated Stink Bug (Halyomorpha halys,            Stål, 1855), which equated to an average of 9.2% kernels            displaying feeding scars and their associated reduction in            quality. Note that no chemical control measures were            utilized and Brown Marmorated Stink Bug pressure is high in            New Jersey. The percentage of good kernels for ‘Raritan’ was            considerably higher than that reported for ‘Barcelona’ in            multiple reports from Oregon (60.9% good kernels reported in            Mehlenbacher et al. [2008] and 69.4% in Mehlenbacher et al.            [2013]). The average percentage of good kernels for            ‘Raritan’ grown in New Jersey is relatively similar to the            range reported from Oregon for ‘Yamhill’, ‘Jefferson’,            ‘Dorris’, and ‘McDonald’; however, the percentage of moldy            nuts was generally lower. There were no instances of            doubles, black tips, or poorly filled kernels for ‘Raritan’.        -   Nut maturity date.—The nuts of ‘Raritan’ are typically borne            in clusters of 2-3 and sometime 4 in husks about 50% longer            than the nuts. The husks are flared and slit down the side            (FIG. 2), and open as they dry at maturity. About 90% of the            nuts fall free of the husk at maturity (range 80-100%). The            other 10% of the nuts come out of the husks as they move            through the harvester. When mature, the shells are tan to            light brown in color. Harvest date on average is around 7            days before ‘Jefferson’ when grown in East Brunswick, N.J.,            typically around first week of September.        -   Incompatibility and pollinizers.—The trees set a moderate to            high amount of catkins that shed pollen in early mid-season            a few days prior to ‘Yamhill’. Pollen has been collected and            used in several controlled pollinations, and both quantity            and viability appear to be good. ‘Raritan’ has            incompatibility alleles S3 and S22 as determined by            fluorescence microscopy. Both alleles are expressed in the            female flowers, but only S3 is expressed in the pollen            because of dominance. By convention, alleles expressed in            the pollen are underlined. Time of pollen shed and female            receptivity were recorded weekly from early December 2017 to            late March 2019 (FIGS. 4-5). Climatic conditions vary each            year and impact dates of bloom but not usually the order of            progression of bloom among cultivars. Female inflorescences            of ‘Raritan’ emerged in early mid-season and were fully            receptive in mid-February (New Jersey). Pollinizer cultivars            that shed compatible pollen in midseason and late midseason            are recommended, with hybrid hazelnut seedlings (Corylus            americana x C. avellana) planted as pollenizers in eastern            and northern regions where cold temperatures and fluctuating            climatic conditions can affect pollen production of C.            avellana. Alternative orchard designs include planting            different eastern filbert blight resistant cross-compatible            cultivars in adjacent rows to augment pollen production.            Flowering times will continue to be observed and pollinizer            recommendations adjusted accordingly. Pollinizers must be            selected that express a high level of EFB resistance to            eliminate/reduce the need for fungicide control in the            entire orchard.        -   Pests and diseases.—Based on field trials under high disease            pressure and greenhouse inoculation trials, both performed            in New Jersey, ‘Raritan’ expresses a very high level of            tolerance to EFB (quantitative resistance). Fungicide            applications to control EFB are not expected to be needed.            Small cankers that may develop can be removed through            pruning to reduce inoculum load in production orchards.            Susceptibility to bacterial blight caused by Xanthomonas            campestris pv. corylina has not been quantified, but the            original seedling tree and clonal trees in the replicated            trials were not affected. Susceptibility to big bud mite            (primarily Phytoptus avellanae Nal.) has not been            quantified, but the original tree and trees in the            replicated trials were not affected.        -   Propagation.—Layers of ‘Raritan’ are vigorous and root well            similar to standard cultivars of Corylus avellana

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What is claimed is:
 1. A new and distinct cultivar of Corylus plantnamed ‘Raritan’, as illustrated and described.